/fusion-plugin-node-performance-emitter

Primary LanguageJavaScriptMIT LicenseMIT

node-performance-emitter

A tool for collecting, aggregating, and emitting Node.js performance stats.

Collects stats on the event loop lag, garbage collection events, and memory statistics. Note that this plugin is server-side only and will throw an error if used browser-side.

Example

// main.js
import App from 'fusion-react';
import Root from './components/root';
import UniversalEvents from 'fusion-plugin-universal-events';
import Analytics from './plugins/analytics';

import NodePerformanceEmitter from 'fusion-plugin-node-performance-emitter';

export default function() {
  const app = new App(<Root />);
  const EventEmitter = app.plugin(UniversalEvents);

  if(__NODE__) {
    const PerfStats = app.plugin(NodePerformanceEmitter, {EventEmitter});
    app.plugin(AnalyticsPlugin, {PerfStats});
  }

  return app;
}

// plugins/analytics.js
export default function({PerfStats}) => (ctx, next) => {
  const perf = PerfStats.of(ctx); // Get an instance of the NodePerformanceEmitter
  perf.start(); // Start collecting stats

  /* do stuff! */

  perf.stop(); // Stop collecting stats
  return next();
}

API

const PerfStats = app.plugin(NodePerformanceEmitter, {EventEmitter, config})
  • EventEmitter - Required. An event emitter plugin to emit stats events to
  • config: Object - Optional
    • eventLoopLagInterval: number - Optional. Stats emission frequency for event loop lag stats. Defaults to 10,000 (ms)
    • memoryInterval: number - Optional. Stats emission frequency for memory stats. Defaults to 10,000 (ms)
    • socketInterval: number - Optional. Stats emission frequency for socket stats. Defaults to 10,000 (ms)

The following events are emitted through the EventEmitter:

  • node-performance-emitter:gauge:event_loop_lag
  • node-performance-emitter:timing:rss
  • node-performance-emitter:gauge:heapTotal
  • node-performance-emitter:gauge:heapUsed
  • node-performance-emitter:timing:gc
  • node-performance-emitter:gauge:globalAgentSockets
  • node-performance-emitter:gauge:globalAgentRequests